Administratrix of the



UNITED sTATEs PATENT OEEICE.

ELIZABETH KEAGY, OF MINERAL POINT, PENNSYLVANIA, ADMINISTRATRIX OF THE ESTATE OF SAINIUEL KEAGY, DEOEASED.

CENTERING-CHUCK FOR LATI-IES.

Specification of Letters Patent No. 27,598, dated March 20, 1860.

To all whom it may concern? Be it known that I, ELIZABETH KEAGY, of Mineral Point, in the county of Oambria and State of Pennsylvania, administratrix of the estate of SAMUEL KEAGY, deceased, do hereby declare that the aforesaid SAMUEL KEAGY did invent a new and Improved Centering-Ohuck for Lathes; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which-- Figure l is a side view of a lathe with the within described invention applied to it. Fig. 2 is a face view of the same.

Similar letters of reference indicate corresponding parts in the two figures.

The object of this invention is to obtain a simple attachment that may be applied to any ordinary turning lathe, and serve as an efficient centering device therefor to admit of the very ready and proper adjustment of articles in the lathe.

The invention consists in placing on the mandrel of the stationary head a sliding thimble or sleeve, having its outer end of flaring form and so arranged relatively with the center points of the mandrel as to effect the desired end.

To enable those skilled in the art to fully understand and construct the invention I will proceed to describe it.

A represents the bed of an ordinary turning lathe; B, its stationary hea-d, and O, the mandrel thereof, provided with center points a.

The above parts may be all constructed in the usual way with the exception of the mandrel O, which is a little longer than usual to admit of a thimble or sleeve D, being placed on its inner end with a requisite degree of play or sliding movement allo-wed it. This thimble or sleeve is allowed to slide freely on the mandrel, and its outer end is of flaring form or funnel-shaped, as shown clearly in Fig. l. The thimble or sleeve is grooved externally and circumferentially to receive the fork at the upper end of a lever E, which is secured in the bed A, by a fulcrum pin at, the lower end of said lever having a cord b, attached, said cord passing over a pulley c, in the bed, and having a weight 4F, at its end-see Fig. l.

The weight F, has al tendency to keep the thimble or sleeve D, thrust out to its fullest extent on the mandrel, and at such a point that the flaring or funnel-shaped end of the thimble or sleeve will project-over the points a, of the mandrel as shown in red Fig. l.

The funnel-shaped interior of the thimble or sleeve is concentric with the mandrel or center points c, and it is designed to have the funnel-shaped end of the thimble or sleeve of suflicient diameter to receive the end of the work or stick to be centered in the lathe.

The operation will be readily seen: The work or stick to be operated on (shown in red, Fig. l) has one of its ends shoved by the operation into the funnel-shaped end of the thimble or sleeve D, and said end, being concentric with the mandrel O, and its points a, will guide and center the stick accurately the thimble or sleeve receding on the mandrel as the stick is pressed inward to receive the points a. Then the stick has been turned it is removed as usual and the weight F, throws the thimble or sleeve out` ward to its original position so that. it may perform the function above described to the succeeding stick. It will be understood, of course, that the other end of the stick is secured by the usual adjustable center point.

Having thus described the invention of SAMUEL KEAGY, deceased, I, as administratrix of his estate, and in trust for the heirs of the aforesaid SAMUEL KEAGY, do claim as new and desire to secure by Letters Patentz- The sliding thimble or sleeve D, fitted on the mandrel C, connected with a loaded lever E, and provided with a flaring o-r funnelshaped outer end concentric with the mandrel and its center points a, to form a centering chuck for a lathe, as set forth.

ELIZABETH KEAGY.

Witnesses:

S. B. OoHIoE, OYEUs L. PERSHING. 

